Internal combustion engine



FIG. 1 is a side view of an internal combustion engine in accordance with the present invention;

FIG. 2 is a rear side view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom view thereof;

FIG. 7 is a referential right side perspective view taken from the front side;

FIG. 8 is a referential left side perspective view taken from the front side;

FIG. 9 is a referential right side perspective view taken from the rear side; and,

FIG. 10 is a referential left side perspective view taken from the rear side. 

The ornamental design for an internal combustion engine, as shown and described. 